1. Field of the Invention
This invention relates to a surgical operating system and one or more devices for performing such surgery. More particularly, the present invention relates to a device that permits effective isolation of an incision while permitting access to a body cavity opened via the incision. Most particularly, the present invention relates to a method for performing video-assisted surgery in a way that minimizes the number and size of incisions to be made during a typical procedure.
2. Description of the Prior Art
For many years most surgery was performed using an open technique. The surgeon made an incision dictated by the need to directly observe the area of interest and to insert his or her hand or hands, and/or one or more instruments to perform manipulations within the body cavity accessed through the incision. Retractors and assistants help to provide means of access. For many procedures these incisions are as long as 20 centimeters, traumatic, and painful. This translates into a painful recovery, prolonged hospitalization with a slow return to a normal functional state, and significant cost.
An alternative to open surgery, endoscopic surgery, has also been available for many years, though not as widely applied. Through an endoscope--a tubular optical system for viewing the interior of an organ or body cavity--tissues can be observed. An endoscope is used by making a small incision in the appropriate body covering. A hollow tube, or port, usually 10-25 cm. in length and 5-30 mm. in diameter, is placed through the incision and the endoscope is placed through the hollow tube. Through various other incisions and ports, other instruments can be placed into a body space for manipulation, grasping, cutting, coagulation etc., similar to open surgery. In the abdomen and pelvis the optical tube is called a laparoscope and the method laparoscopic surgery.
This laparoscopic surgical method usually includes a step of expanding the body cavity with air, inducing a state of pneumoperitoneum, which enhances the surgeon's view and ability to make manipulations. This is accomplished by one of two techniques, air insufflation or abdominal wall lifting. Abdominal wall lifting creates negative pressure within the cavity in relation to the atmosphere, drawing in air through a small incision when the wall is lifted. The disadvantage with this technique is that observation is imperfect. A tent is created with a central peak and a collapsed perimeter. Though most structures have midline attachments, most endoscopic manipulations take place in the periphery. This is where visualization with this technique is worst. Insufflation is a positive pressure system using a medicinal vapor such as carbon dioxide or nitrogen injected into the peritoneal cavity to balloon the abdominal wall. Expansion is more uniform. Vision is better. This is the most widely used technique. Because of the positive pressure, however, the abdomen must be sealed to maintain expansion. This requires that all incisions and ports be sealed. Insufflation also has adverse respiratory and hemodynamic consequences due to positive pressure inhibiting chest expansion and venous blood return to the heart.
Though endoscopic surgery has been available for many years, it's application has increased recently due primarily to the development of video monitoring equipment. This has allowed all members of the surgical team to observe, though indirectly, what only the surgeon could previously observe through a laparoscope. In some cases visualization is better than with direct observation. This has led to renewed interest and investigation of these techniques.
The benefit of endoscopic surgery is the limited incisional trauma, improved cosmesis, and decreased pain. For several simple techniques, such as laparoscopic cholecystectomy, this has translated into decreased hospitalization and earlier return to normal function, though cost savings is debated.
While some open surgical procedures have been adapted to laparoscopic technique, there are limitations with this method, particularly with more complex procedures. Fundamental problems relate to the access tubes used for inserting the various manipulative instruments. While limiting incisional trauma, the small diameter of these tubes dictates and limits the design of the inserted instruments. To achieve similar function as in open surgery, equipment becomes complex and therefore more expensive. There is also added risk with each access tube. Each tube requires a stab-wound of the body wall, risking injury to contained viscera with each puncture.
Equally important has been the impact on the surgeon's ability to manipulate tissue. The visual field may have been improved. However, tactile sensation, depth perception, and proprioceptive awareness of tissues have been markedly reduced by instruments which insulate the surgeon from the operative field. As the surgeon continually confirms that that which is done is that which is desired, procedural and anesthesia time increase. Furthermore, the limited access enabled by each port dictates that multiple ports be used. As procedural complexity increases, the surgeon must adapt to a continuously changing and less predictable environment than with simple procedures. The number of ports, and the risk and incidence of complications increases. The requirement for highly skilled and coordinated surgical teams also increases. This has resulted in long learning curves and has limited wide application of these procedures for complex cases.
One device apparently designed to assist in endoscopic procedures is described in U.S. Pat. No. 5,366,478 issued to Brinkerhoff. Brinkerhoff teaches a toroidal unit that is designed to be inflated so as to create an apparent sealing component through the center of which an arm or instrument is supposed to pass. However, Brinkerhoff specifically states that the "approximate height of the first (exterior) toroidal section 11 should be at least 2 inches to safely support an endoscopic instrument when the surgeon is not handling the instrument" (Col. 5, lines 23-26, of Brinkerhoff) Not only must the first toroidal section of the Brinkerhoff device be tall enough to support an instrument, it must inherently be stiff enough to do so, while also maintaining a seal. It is clear that in order to maintain a seal, a hand passing through the center of the device must be significantly restricted. The pressure and surface area of the device on the hand must limit forward and rotational movement within and below an incision. In addition, the overall height of the device, including those portions above, within, and below, the incision produces a fulcrum of significant overall length. It would be difficult, if not impossible, for a surgeon to reach all regions within the peritoneal cavity with the hand or an instrument, particularly those areas lateral to the incision and just below the body wall. The specific design of this device ultimately limits its purpose: to permit access to, and operation within, the peritoneal cavity.
A secondary problem associated with the Brinkerhoff device relates to the need to keep it inflated in order to effect a seal. The application of pressure to keep the device operable renders this device subject to unexpected failure, whether by a defect or weakness in the material, or by a failure of the equipment used to maintain the pressure. If the need to keep a seal of the incision is important, such concerns render the Brinkerhoff device less than suitable.
Another problem related to limited access occurs with procedures requiring specimen removal. While some specimens have been removed through the small access incisions, and others removed through innovative approaches--e.g., the vagina--many require a separate incision for removal. However, these incisions have generally been smaller than those of open procedures and have preserved most of the benefit of a laparoscopic approach.
Some surgeons have adopted modified laparoscopic approaches when specimen removal is an issue. Internal observations and some manipulations are performed with insufflation via laparoscope. Some manipulations and specimen retrieval are performed without insufflation through a small 4-6 cm. incision. Some surgeons have placed their hands into the wound under laparoscopic visualization and with insufflation. The seal is maintained by securing the abdominal wall to the hand with surgical ties attached to the abdominal wall. These approaches still contain many negative aspects. The pure laparoscopic portion is performed with diminished perception, as outlined above. The pure open portion is performed at the level of the skin with almost no access to the body cavity. In addition, combined approaches can be difficult. Committing one hand to the abdominal cavity limits a surgeon's usefulness for other tasks. The option of withdrawing the hand is therefore desirable. However, conversion from one approach to the other is difficult because the larger incision must be resealed on each occasion to reestablish pneumoperitoneum. This added time limits it's frequent use, though this is increasingly desirable with increasing operative complexity.
Finally, there has been concern about wound contamination during laparoscopic surgery particularly the implantation of tumor cells. The etiology of this problem is unclear. It may be a systematic problem with a particular element of the technique such as insufflation where positive pressure venting through the incision results in contamination. Another systematic problem might be direct contamination during specimen removal. The anecdotal occurrence of these problems suggests a more isolated and less systematic error, such as poor tissue handling technique. However, these concerns and the lack of understanding have limited the application of the technique.
What is needed is a surgical technique that combines the observational advantages of an endoscope and the tactile sensation of traditional open surgery. What is also needed is a surgical technique that minimizes the size and number of incisions required to perform operations, particularly abdominal operations, yet preserves the surgeon's ability to change with the changing requirements of complex operations. Still further, what is needed is a surgical device that permits the simultaneous use of endoscopic observation in combination with the advantage of physical contact with that portion of the body operated upon. What is yet further needed is a device that facilitates procedures using both endoscopic and tactile approaches, allows quick conversion between approaches, and therefore increases the surgeon's flexibility to choose the best approach. What is also needed is a device that can be used in video-assisted surgery, that can effectively maintain insufflation of the body cavity when that technique is used, and that can be used to minimize or prevent wound contamination.